The structure of the binary CoA–AcpSVC complex. (a) Interaction of CoA/K at the interface of the AcpS/K and AcpS/J protein molecules of the AcpSVC/J/K/L trimer. CoA is colored according to its atoms: C, light yellow; N, blue; O, red; P, orange; S, dark yellow. (b) Examples of CoA molecules with well defined (CoA/K) and poorly defined (CoA/N) electron densities. The 2Fo − Fc maps are contoured at 1.0σ. The modeled 3′,5′-ADP molecule at the CoA/N binding site is shown as purple sticks. (c) Coordination of CoA/K. (d) and (e) show the two calcium-binding sites, Ca-I and Ca-II. The coordination of CA2513/C in (d) is equivalent to that of CA2527/J in (c).